I have gotten 7 window quotes (well, 8, one contractor quoted me for 2 different brands). Of course EVERY contractor says the brand they sell is the best, and makes faces about the other brands. Online information is spotty and it seems to depend so much on region and model year (do they have model years? There seems to be so much revision) and so much, I'm finding it very hard to compare apples to apples. Maybe all you smart window savvy people can help bring some piece of mind to my decision.

I am replacing all 7 of my windows (sliders) and a sliding door. Currently I have single pane aluminum frame windows with most of the calking surrounding them cracked (so basically nothing at all efficiency wise). I live in Denver, CO, and all windows are east facing.

I'm leaning toward the Zen Karma ($7165). Mostly they have a great warranty that covers everything, I like the antimicrobial weather stripping, and I haven't found any negative reviews yet.

My other options, in order of consideration:

Amerimax. My choice of Masters grande or Craftsman. $5500.
Simonton Assure. With a vague promise that the quote included the "better glass package" $7475
Milgard Tuscany, with LowE3

I've disregarded the quotes for Cascade, soft-lite barringtons, American Exteriors, and Champion.

So I guess what my question boils down to is: Is the Karma (soft-lite classic I believe) worth the 25% premium over the Amerimax? I'd rather spend the little bit extra to get a better product, but don't want to throw money away if not beneficial.

If you can find a Softlite or Sunrise product from a reputable company that has been around for more than a few years, that would be ideal. Sounds ridiculous of course to get any MORE estimates as you already have 7, but only one good one is all that's needed.

Of the options on the table, what disqualified the Barrington guy for you?
... On Amerimax, I've heard generally decent feedback on that window from pros out west, but like WoW I don't have personal experience.

As far as sorting through things, as I alluded to above, find a reputable dealer with some history and good reviews. On product, look at the performance ratings. U value, shgc, Cr, Air leakage, dp, etc. That takes a lot of subjectivity out of it for you.